Field of the Disclosure
The present disclosure relates to a data transmission device for modulating the amplitude of a 4-level Pulse Amplitude Modulation (PAM-4) signal using a toggle serializer and a method of operating the same, more particularly to a data transmission device for modulating the amplitude of a PAM-4 signal by generating at least one toggle signal according to logic level change in a Most Significant Bit (MSB) signal and Least Significant Bit (LSB) signal included in a PAM-4 signal and combining the at least one toggle signal with a PAM-4 signal, and a method of operating the same.
Description of the Related Art
Recently, as the use of multimedia data communication has rapidly increased, high-speed data transmission of high-capacity data is required, and the operation speed has reached 1 Gb/s or more. Accordingly, a Pulse-Amplitude Modulation (PAM) manner, which is more advantageous, at high speed, than high-speed data transmission adopting a conventional Non-Return-to-Zero (NRZ) manner, is widely used.
In particular, a PAM-4 transmission manner has an advantage of being able to operate at about 2 times slower speed in transmitting the same data amount as compared with existing NRZ data transmission manner. However, despite such an advantage regarding speed, electronic channels, such as a Printed Circuit Board (PCB) transmission line, still cause speed limitations in data transmission.
To address such a problem, a pre-emphasis function among equalizing schemes (e.g., pre-emphasis, a continuous time linear equalizer, a decision feedback equalizer, etc.) which have been used for NRZ data transmission is attracting attention.
However, an existing pre-emphasis function is not suitable for a PAM-4 signal. To address this, a pre-emphasis function for a PAM-4 signal has been performed using two structures configured to perform an existing pre-emphasis function. However, this method has a problem of high power consumption and that a large chip area is required.
To address the aforementioned problems, there is a need for a technology to perform a pre-emphasis function for a PAM-4 signal which provides a chip area gain while reducing power consumption.